In applying the Pearson's Square, which operation is performed across the diagonal first?

In applying the Pearson's Square, which operation is performed across the diagonal first?

• A. Subtract across the diagonal
• B. Multiply across the diagonal
• C. Divide across the diagonal
• D. Add across the diagonal

Answer: (A)

In Pearson's Square the key step is to form the mixing ratio from differences between each ingredient's percentage and the desired percentage. The first operation across the diagonal is subtraction: you subtract the target percentage from each ingredient's percentage. These two diagonal differences become the parts of each ingredient in the final mix—the larger the difference, the more of that ingredient is needed relative to the other. For example, to hit a 12% target using ingredients at 5% and 60%, you compute 12 − 5 = 7 and 60 − 12 = 48. Those differences give the mixing proportions (7 parts of one ingredient and 48 parts of the other). The actual amounts are then scaled to total your desired quantity. Multiplication, division, or addition across the diagonal isn’t how the initial mixing ratio is determined in this method.

In Pearson's Square the key step is to form the mixing ratio from differences between each ingredient's percentage and the desired percentage. The first operation across the diagonal is subtraction: you subtract the target percentage from each ingredient's percentage. These two diagonal differences become the parts of each ingredient in the final mix—the larger the difference, the more of that ingredient is needed relative to the other. For example, to hit a 12% target using ingredients at 5% and 60%, you compute 12 − 5 = 7 and 60 − 12 = 48. Those differences give the mixing proportions (7 parts of one ingredient and 48 parts of the other). The actual amounts are then scaled to total your desired quantity. Multiplication, division, or addition across the diagonal isn’t how the initial mixing ratio is determined in this method.